Question

determine the number of neutrons in one atom of barium. you must round the atomic weight to the nearest whole number. then, subtract protons to get neutrons. barium has ___ neutrons.

Explanation:

Step1: Find Barium's atomic number

The atomic number of Barium (Ba) is 56, so the number of protons = 56.

Step2: Round Barium's atomic weight

Barium's atomic weight is ~137.33, rounded to the nearest whole number is 137.

Step3: Calculate number of neutrons

Neutrons = Rounded atomic weight - Number of protons
$\text{Neutrons} = 137 - 56$

Answer:

81